Laminated Vibration-Proof Rubber Covering for Flame and Cold Resistance
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Solution Overview
Problem
Existing laminated vibration-proof rubber for railway vehicles faces challenges in achieving balanced flame retardancy, cold resistance, and durability, particularly due to differences in hardness between the fireproof layer and the elastic portion, which can lead to peeling issues in low temperatures and mechanical property deterioration.
Innovation Solution
A laminated vibration-proof rubber design featuring a natural rubber-based elastic layer alternately laminated with hard layers and covered with an isoprene rubber-based covering layer, where the covering layer has higher flame retardancy than the elastic layer, ensuring close bonding and maintaining flexibility across temperature variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a CR-based rubber is used as the fireproof layer to improve flame retardancy, then flame retardancy is improved, but cold resistance deteriorates due to hardness difference between layers
Solution Approach 1:
The patent applies local quality by using different rubber materials for different layers: the elastic portion uses NR-based rubber for elasticity, while the fireproof layer uses CR-based rubber for flame retardancy. This localized material selection allows each layer to perform its specific function optimally without compromising overall performance.
Solution Approach 2:
The patent employs composite materials by combining CR-based rubber with specific additives (TAIC and DCP) to create a fireproof layer that maintains both flame retardancy and bonding compatibility with the NR-based elastic portion, resolving the hardness difference issue through material composition optimization.
2Object-affected harmful factors
If a CR-based rubber is used as the fireproof layer to improve flame retardancy, then flame retardancy is improved, but durability deteriorates due to peeling in low temperature environments
Solution Approach 1:
The patent introduces TAIC and DCP as intermediary substances that facilitate bonding between the CR-based fireproof layer and the NR-based elastic portion. These additives act as mediators that enable cross-layer adhesion, preventing peeling and improving durability in low-temperature environments while maintaining flame retardancy.
Solution Approach 2:
The patent applies parameter changes by modifying the chemical composition of the CR-based rubber through the addition of TAIC and DCP, which alters the bonding parameters and allows the fireproof layer to maintain strong adhesion to the elastic portion across a wide temperature range, thereby improving durability.
3Object-affected harmful factors
If flame retardants such as metal oxides are blended with natural rubber to improve flame retardancy, then flame retardancy is improved, but mechanical properties deteriorate
Solution Approach 1:
The patent extracts the flame retardancy function from the elastic portion material and relocates it to a separate fireproof layer made of CR-based rubber. This extraction allows the elastic portion to maintain its original NR-based composition with excellent mechanical properties, while the fireproof layer provides the required flame retardancy.
Solution Approach 2:
The patent segments the vibration-proof rubber into distinct functional layers: an elastic portion for mechanical performance and a fireproof layer for flame retardancy. This segmentation allows each layer to be optimized independently, with the elastic portion maintaining high tensile strength through pure NR-based rubber and the fireproof layer providing flame protection.
Data Source
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AI summary
A laminated vibration-proof rubber includes: a main shaft; an outer cylinder disposed concentrically with a shaft center of the main shaft; an elastic portion interposed between the main shaft and the outer cylinder, the elastic portion having a configuration in which a plurality of elastic layers and one or a plurality of hard layers are alternately laminated in a radially inner and outer direction with respect to the shaft center; and a covering layer covering at least the elastic layers, in which the elastic layers contain natural rubber as a main component, and the covering layer includes a rubber composition containing isoprene rubber as a main component, and has flame retardancy higher than that of the elastic layers.